I have looked at the message board and read the technical article, I just wanted to make sure I had the plumbing correct for a trans cooler. Sorry for the crappy drawing. The red line is oil leaving the trans and the blue lines are oil coming out of the radiator and trans cooler then back to the trans. Please check to make sure I am correct, thanks in advance.

I recently did my tranny cooler and that diagram looks correct.

Lots of people here have their own opinions on how it should be done, and they all seem to work. Sometimes I think there might be no "wrong" way to do it.

Thanks for the replies. I thought that the way I was going to plumb it was correct, just wanted to make sure.

There is an arguement that you can over-cool the fluid. If you run it through the air exchanger first, the fluid going back to the tranny will be engine coolant temperature.

If, however, in stop & go driving your coolant temp gets up to 240 degrees F, you're cutting your fluid life about in half vs. 190 degrees (assuming petroleum based fluid - AMSOIL ATF, for instance, is quite happy at 240 degrees F).

If I primarily drive on the highway, should I run it through the external cooler first and then the radiator, or just run it through the cooler in the radiator and not even worry about using an additional external cooler? I plan on eventually building the L98 in the car now so that it has around 400 HP, I figured I would definitely need an external cooler in series then.

There are lots of arguments both ways. I have mine routed through the factory cooler first. Here are some of my observations: https://www.thirdgen.org/techbb2/sho...hreadid=131095

Now do the same thing routing it to the external first...

I have heard of guys who run it through the radiator cooler first during summer, and switch it to external first in winter.

Of course, if you routed it to the radiator first, got a thermostatic by-pass that only took it through the external when needed, that would resolve it.

FWIW, I also got a manual tranny Griffin for the '57 back in '98 when I put in the 396. That wasn't a mistake, though - this one cost me $300, an automatic version was going to run over $500. I had only been using a 4-tube external until this spring, when I put a 6-tube on the radiator, then continued on to the 4-tube remounted on the grill (I went from a 2200 stall to 3500 stall converter late last racing season). The tubes of the 4-tube will often be cool to the touch now after getting back to the pits after a run.

As I recall I was going to do it that way, but then didn't for some reason. If I was more interested in pure science I'd try it both ways, but it works now so I don't feel like messing with it. I've thought about a thermostatic bypass valve, Permacool makes one that closes at 180 F.